PT772894E - FEEDING TROMPA DESTINED IN SPECIAL TWO-WAY EQUIPMENT FOR COMMUNICATIONS BY SATELLITE - Google Patents

Abstract

PCT No. PCT/SE95/00878 Sec. 371 Date Jan. 27, 1997 Sec. 102(e) Date Jan. 27, 1997 PCT Filed Jul. 20, 1995 PCT Pub. No. WO96/04693 PCT Pub. Date Feb. 15, 1996A feeder horn for two-way satellite telecommunications includes a center transmitter/receiver horn (10) and at least three separate measuring (11, 12, 13) which are positioned symmetrically relative to the symmetry (O) of the feeder horn. All horn are produced mechanically in a one-piece metal structure (1) which includes the transmitter/receiver horn (10) accommodating and through-penetrating a center opening (100) which merges with a transmitter waveguide (101) and a receiver waveguide (102) which are separated by a filter of the orthomode transducer type (OMT), which is constructed for separating differing polarizations and comprises an output to the center opening (100) of the metal structure and two inputs to respective waveguide for the transmitter and receiver waveguides; wherein the metal structure further includes a bottom-defined opening (110, 120, 130) for each of the measuring horns, a switching device (111, 121, 131) anchored in the metal structure for each of the measuring horns and moat-like channels (104, 114, 124, 134) provide around each opening (100, 110, 120, 130) in the metal structure, to isolate electromagnetically each horn in relation to each other horn.

Description

DESCRIPTION "Feeding horn intended in particular for two-way equipment for satellite communications"

TECHNICAL FIELD The present invention relates to a feeder horn intended in particular for two-way satellite telecommunications equipment, and more in particular to such a horn which includes a central transmitter / receiver horn and at least three separate measuring horns which are symmetrically positioned relative to the line of symmetry of the feeder tube.

DESCRIPTION OF THE PREVIOUS ART

The mechanical and electrical components of the satellite communications equipment intended in particular for marine applications must be of very good quality in order to ensure a smooth and continuous operation time of at least about two years before a failure occurs. It may be mentioned as an example that the available mechanical turns do not provide information when very small changes occur in three-dimensional space. The mechanism of such turns is hampered by a very large intrinsic inertia that makes it unable to handle information quickly enough to compensate for the small but rapid changes that the equipment can be subjected to in a maritime environment.

Such an apparatus includes control systems which receive input data from the transmitters in positioning systems. This input data is updated for nonlinearity and operation due to thermal influences in electronic systems among other things, by active calibration against a "true" signal. and, the signal which is received by an antenna and which originates from the target object, the satellite, for which the elevation and azimuth are well defined for those geostationary satellites which may constitute a reference for the "true" calibration. It is only possible to satisfy the required follow-up with the accuracy of 0.1 ° when using a highly effective and efficient tracking system that is Ρ Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο Ο V, fast enough to continuously follow the signals transmitted by the satellite and to record any deviations that may occur in the X: Y: Z directions. Those products that are commercially available at the moment are associated with very high investment costs (on the order of about SEK: 1 000 000). In addition, it is difficult to find technical solutions that can reduce the cost through large-scale manufacturing. The object of the present invention is to eliminate said drawbacks of a technical and economic nature.

SUMMARY OF THE INVENTION The novel and inventive feeding tube is based on the basic concept of the production, solely by mechanical means, of a physical phase difference between the input signals.

Characteristic aspects of an inventive feeder horn are highlighted in the following claim 1. Embodiments of the inventive feed horn are defined in claims 2, 3 and 4.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying schematic drawings, in which: Fig. 1 schematically illustrates one embodiment of an inventive feed tube viewed from above; and Fig. 2 is a side view of the horn shown in Fig. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated feed tube includes a centrally positioned transceiver horn 10 and four separate metering horns 11, 12, 13, 14 which are arranged symmetrically with respect to the symmetry line 0 of the feed tube at right angles to the drawing plane.

87 427 ΕΡ Ο 772 894 / ΡΤ 3

All tubes are produced mechanically in one and the same metal structure 1. The transceiver horn 10 has a through aperture 100 which is connected to a transmitting waveguide 101 and a receiver waveguide 102 which are separated by a filter type transducer 103 (one OMT - filter). Each of the measuring tubes 11, 12, 13, 14 has a lower limit opening 110, 120, 130, 140. The one-piece metal structure 1 has disposed therein a switching device 111, 121, 131, 141, e.g. shape of a measuring probe, for each respective measuring horn.

A well-type channel 104, 114, 124, 134, 144 is provided around each respective aperture 110, 110, 120, 130, 140 to thereby electromagnetically isolate each horn relative to the others. The aforementioned power horn having four measuring horns 11, 12, 13, 14 is for satellite communications with a relatively small frequency difference between the transmit and receive frequencies, for example a frequency difference of 1 : 1.05. The central aperture 100 is square in shape and the sides of the apertures 110, 120, 130, 140 of the metering horns 11, 12, 13, 14 and the sides of the well-like channels 114, 124, 134, 144 are essentially parallel with respect to each other. to the corresponding sides of the aperture 100 and to the well-like channel 104 in the transceiver horn 10.

A slightly modified embodiment of the feeder horn is intended for satellite communications with a relatively large frequency difference between the transmit frequency and the receive frequency, for example a frequency difference of 1: 1.5. The measuring tubes are still four in number, but the central aperture 100 and the well-like channels 104 are of a circular shape and the sides of the apertures 110, 120, 130, 140 of the measuring tubes 11, 12, 13, 14 and the sides of the well-like channels 114, 124, 134, 144 are essentially parallel to the corresponding sides of the aperture 100 and the well-type channel 104 in the transceiver horn.

Alternatively, the feeder tube 10 may be provided with three symmetrically positioned measuring tubes 11, 12, 13. The openings and well-like channels may also be square or circular in this case, depending on whether the difference between the transmission frequency and the receiving frequency is small or large.

If an antenna having a feeder horn including four measuring horns is rotated to produce a frequency diagram for a signal received by the measuring horns and transmitted from a satellite, a common intersection point is obtained; this point will represent the condition in which all four measuring heads are equally displaced from the signal source (the satellite), i.e., the antenna reflector is optimally directed to the chosen satellite. The feeder horn equipped with four measuring horns can be produced to a degree of accuracy that will satisfy the requirement of at least 40 Db insulation between the measuring tubes and an insulation of at least 100 dB between the fallopian tubes. and the transceiver tube. This means that transmission powers of about 100 watts within the 14 GHz band can not give rise to a given increase in electromagnetic noise in an adjacent measuring horn present in the same metal structure and having a reception frequency within the band of 12 GHz. Calculations indicate that the construction itself guarantees an economically viable mass production. It can be envisaged that mass-produced constructions will cost no more than one tenth of the cost of the corresponding constructions produced in accordance with known techniques. 9

It may be mentioned that the lower defined apertures (110, 120, 130, 140) of the measuring tubes allow external filters to be connected to the measuring tubes (11, 12, 13, 14) and that the switching devices (111, 121, 131 , 141) attached to the one-piece metal structure (1) allow measuring probes to be placed after connecting an external waveguide filter to each of the measuring tubes.

Lisbon, * ·· <! 0U1

By C2 Sat Communications AB - THE OFFICIAL AGENT -

Eng. ° ANTÓNIO JOÃO DA CUNHA FERREIRA Ag. Of. Pr. Ind. Rua das Flores, 74-4 ° 1200 * 195 LISBOA

Claims (4)

A feeding horn intended in particular for two-way satellite telecommunications equipment including a central transmitter / receiver horn (10) and at least three separate measuring horns (10). 11, 12, 13), which are positioned symmetrically with respect to the symmetry line (0) of the feeder tube, characterized in that all the tubes are mechanically produced in a one-piece metal structure (1) including a trumpet (10) which accommodates a central through aperture (100) to be connected to a transmitting waveguide (101) and a receiver waveguide (102) which are separated by a orthodon transducer type filter (103) ( OMT), which is constructed for different separate biases and comprises an outlet for the central aperture of the metal structure and two inputs for respective waveguides for the transmitting and receiving waveguides ; in which the metal structure further includes a lower limit opening (110, 120, 130) for each of the measuring tubes (11, 12, 13), a switching device (111, 121, 131) fixed to the structure of metal (1) for each of the measuring horns (11, 12, 13), and well-like channels (104, 114, 124, 134) provided around each apertures (100, 110, 120, of metal, to electromagnetically isolate each horn relative to each of the other horns. Feeding horn according to claim 1, characterized in that the measuring horns (11, 12, 13) are three in number. Feeding horn according to claim 1, intended for satellite communications with a relatively small difference between the transmission and reception frequencies, characterized in that the measuring tubes (11, 12, 13, 14) are four in number; in that the central aperture (100) is square in shape; (114, 124, 134, 144) are substantially parallel to the corresponding sides of the aperture (100) and to the sides of the apertures (110, 120, 130, 140) of the metering tubes and the sides of the well- (104) into the transceiver horn. Feeding horn according to claim 1, intended for satellite communications with a relatively large difference between the transmitting and receiving frequencies, characterized in that the measuring horns (11, 12, 13, 14) are in the number of four; in that the central aperture (100) is circular in shape; (110, 120, 130, 140) of the measuring tubes and the sides of the well-like channels (114, 124, 134, 144) are substantially similar to the corresponding sides of the aperture (100) and to the well-type channel (104) of the transceiver horn. Lisbon, By C2 Sat Communications AB - THE OFFICIAL AGENT -